Everything was working great for almost 6 months but yesterday while my pc was idle suddenly some graphic display glitches came up and my keyboard and mouse froze up, so I had to do a hard reset by pressing the power button.

Everytime when windows login screen come up, I see some graphic display glitches like horizontal grey lines and soon after that system crashes and I have to do a hard reset.

If I boot in safe mode I can use the device manager to uninstall the AMD 7800 driver which replaces it with the stock "Standard VGA Graphics Adapter" drivers, then reboot in normal mode and everything works.

I only get the crashes if I Install Catalyst and let the system reboot.

I've already tried Fresh install of Windows 7, Driver Sweeper and re-installing different versions of catalyst like 12.11 and 13.4 but still same issue. I was using 12.11 beta for 6 months but never faced any problem.